Telephone system.



E. R. LUNDIUS.

TELEPHONE SYSTEM. APPLICATION FILED DEC-26,1917.

//1 Van/0r: fr/c R. L and/us.

UMTED s'ra'rns PATENT ora ion.

ERIC R. LUNDIUS, OF BROOKLYN, NEW YORK, ASSIGNOR T0 WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OE NEW YORK.

' TELEPHONE SYSTEM.

Specification of Letters Patent.

Application filed December 26. 1917. Serial No. 208.830. I

To all whom it may concern: a

Be it known that I, ERIC R. LUNDIUs, a citizen of the United States, residing at Brooklyn, in the county of Kings, State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description. 7

This invention relates to telephone systems and more particularly to such systems employing a ring-up relay responsive to ringing current for controlling signaling devices. 7

The principal object of this invention is to provide an improved signaling means for said systems.

In telephone systems employing a ringup relay in series with a condenser and responsive toringing current for controlling a signaling device, considerable difl'iculty has been experienced, due to the false operation of this relay when the answering operator or the originating subscriber or operator disconnects. In the system embodying the present invention. this difliculty is overcome by providing a discharge path for the condenser When the operator responds to the call. 7

This invention will be more fully understoodfrom a consideration of the following description in connection with theaccompanying drawing, illustrating one embodiment thereof.

As shown in the drawing, the trunk circuit B extends from an originating operators position X to a terminating operators position Y. At the position X there is provided a cord circuit A, adapted for connection with the outgoing terminal of the trunk circuit B, while at the position Y is located line signal controlled apparatusand switching apparatus for connecting the answering operators telephone set with the trunk circuit B.

The originating operator in establishing a connection with the trunk circuit, inserts plug 5 in jack 6 and actuates ringing key 7, thus connecting a source of current 8 therewith. The ring-up relay 9 is thereupon operated over a circuit from a source of current 8 through the lower contact of ringing key 7, ring contacts of the plug 5 and jack 6, left-hand normal contact of cut ofi relay 13, condenser 10, left-hand winding of the ring-up relay'9, tip contact of the jack 6 and plug 5, and upper contact of ringing key 7 to ground. Relay 9 in operating causes the intermittent lighting of line lamp 11 over a circuit from battery, through line lamp 11, right-hand contact of relay 9 and interrupter 12 to ground. Relay 9 in operating also establishes a locking circuit for itself through its right-hand winding and left-hand contact, and right hand normal contact of cut-oil relay13 to ground. The operator at Y,;upon observing the intermittent glow of line lamp 11, actuates listening key 14 which, through its upper and middle contacts, connects an 'operators telephone set (not shown)- across the trunk circuit. Cut-ofl' relay 13 upon the actuation 'of'the I listening key 14: is energized over a circuit left-hand alternate contact, the condenser 10 is thereupon included in a closed circuit with the line Winding of relay 9, thus establishing a discharge path for the condenser. The opening of the right-hand normal contact of'the cut-oil relay 13, opens the locking circuit of relay 9, thus causing its release, which in'turn excludes the interrupter 12 from the line lamp circuit. The closing of its right-hand alternate contact causes the continuous illumination of line lamp 11 over a circuit from grounded battery through line lamp 11 and left-hand alternate contact of cut-ofi' relay 13 to ground.

In systems heretofore employed in which the energizing winding of the ring-up relay and the condenser remain connected with the line after the terminating operator answers, the condenser is then charged. When the operator disconnects from the line, there is a surge of current over the line due to the interruption of the circuit and since the condenser is already charged, very frequently causes the discharge thereof, resulting in the energization and locking up of the ring-up relay which causes a false signal. By having the condenser in a discharged eration "of relay 9 is thus prevented by the insertionof condenser 10 in series with the line winding of relay 9; V

What is claimed is: 1 I 1. A telephone system comprising a tele phone lineterminatingat a switchboarcha relay and a condenser connected in series,

in bridge=of the telephone line, a signaling deviceoperated by the relay in response to signalingcurrentimpressed on-the line, an operator controlled switch, and means re sponsive to' the actuation of the-switch to establish a closed circuit including; the 1 con denser for causing the; discharge thereof.

2. A telephone system comprising. a telephone line terminating ata switchboard, a v

relayand a-condenserconnect'ed in series,

in bridge ofthe telephone line, a signaling deviceoperated by the relay in response to signaling current impressed on the line, an operator controlled switch, and an electromagnetic switch responsive to the-actuation of the switch toestablish a closed circuit including the condenser for causing the discharge thereof.

3. A telephone system comprising a telehone lineterminatin at a switchboard arelay and a condenser connected in series,

in bridge of the telephone'line, a signaling deviceopera'ted by the relay in response to the signaling current lnipressed on the line, an operatorstelephone set, means forconnecti'ng the telephone set to saidptelephone line, and means controlled-by said connect 7 mg: means to establish a closed: circuit including the condenser for causing the discharge thereof.

4. A telephone system comprisinga telephone line terminating at a switchboard, a relay and a condenser connected in series, in bridge of the telephone line, a signaling device operated by the relay in response to signaling current impressed upon the line,

an operators telephone set, a manually operated key for connecting the telephone set to said telephone line, and'a relay. controlled from thecontacts of said key toestablish a circuit including the condenser for causing the'discharge thereof. 7

5.v A telephone system COlTlPllSlllgzZL telephone line terminating at a switchboard, a

.relay and a condenser connected in series,

in bridge of the telephone line, a signaling deviceopera'ted-by the relay inresponse't-o signaling current impressed on the line, an

sponsive to the actuation of the switch'to remove the bridge from the telephone line and simultaneously to connect the condenser in aclosed circuit with the line winding of the relay, thereby causing thedischargeof.

the condenser. v

6. A telephone system comprisinga telephone hne terminating at a switchboard, a

relay and a condenser connected in series,

in bridge of the telephone line, a signaling device operated by the relay in responseto signaling current impressed on the line, an operator controlled switch, and an electromagnetic I relay responsiveyto the actuation of theswitch to' remove the bridge from the telephone line and simultaneously to connect the condenser in a closed circuit with a windingjof thefirst mentioned relay thereby causing the discharge of the condenser. V

In witness whereof I hereuntosubsc-rlbe voperatorcontrolled switch, and means 1e 7 my name this 20th day of December A. D.,

' ERIC Ri rum-ms Copies of this patent may, be obtained for dive cents, each, by addressing the Commissioner of Patents;

' Washington, D. v0. V 

